Moore defined plant layout as, “The plan of or the act of planning, an optimum arrangement of facilities, including personnel, operating equipment, storage space, materials handling equipment and all other supporting services along with the design of the best structure to accommodate these facilities”.
There are three basic types of plant layouts and these correspond to the three types of processing systems. Product layouts are most conducive to continuous processing, process layouts are used for intermittent processing and fixed position layouts are used when projects require layouts.
1. Product Layout
Product layout is used to achieve a smooth and rapid flow of large volumes of products or customers through a system. This is made possible by highly standardized products or services which require highly standardized, repetitive processing operations. A job is divided into a series of standardized tasks, permitting specialization of both labor and equipment. The large volumes handled by these systems usually make it economical to invest substantial sums of money in equipment and in job design. Because only one or few very similar items are involved, it is feasible to arrange an entire layout to correspond to the technological processing requirements of the product or service involved.
This layout is for product focused systems, and are popularly known as ‘Assembly Line”. The work centers are arranged in the job sequence. The raw materials enters at one end of the line and individual operations are performed in the pre-fixed sequence and get converted to the final shape. There is one flow for each product. The work in-process and the material handling are minimum.
Following conditions favor the selection of product layout.
- High volume of production
- Standardization of product
- Reasonably stable product demand
- Uninterrupted supply of material
- Holding up of inventory is possible.
Product layouts achieve a high degree of both labor and equipment utilization, and this offsets the high equipment costs. the investment in work-in-process is minimum because the items move quickly from operation to operation. This also reduces congestion and ensures smooth flow of items in the shop floor. Overall supervision and control are effective.
2. Process Layout
These layout are designed to facilitate processing items or providing services which present variations in their processing requirements. The processing units are organized by functions into departments on the assumption that certain skills and facilities are available in each department. Similar equipments and operations are grouped together. For example, turning, milling, foundry, heat treatment. Items which require these operations are frequently moved in batches to the departments in a sequence dictated by technical considerations. Different products may cal for different processing requirements and different sequence of operations. Consequently, variable path material handling equipment is needed to handle variety of routes and items.
These layouts, also known as “Functional Layout’ is process focused systems and are used widely in manufacturing and service sectors. The use of general purpose machines provides flexibility necessary to handle a wide range of processing requirements. Workers who operate the equipments are usually skilled or semi-skilled. The example of process layout includes hospitals, colleges and universities, banks, airlines and public libraries. For instance, hospitals have many departments like surgery, maternity, emergency, etc. Similarly universities have separate departments that concentrate on different areas of study as engineering, business management, mathematics, and physics. In business organization, there will be departments like accounts, personnel, and systems.
Because process layouts arrange equipments by type rather than according to processing sequence, the system is much less vulnerable to shutdown caused by either mechanical failure or absenteeism. Material handling in inefficient and unit handling costs are generally much higher than in product layouts. The investment in work-in-process is high and material movements will take a zig-zag route. The equipment utilization comparatively will be less. Hence, this layout is more suited for low volumes of production and particularly when the product is not standardized. It is economical when flexibility is the basic system requirements.
3. Fixed Layout
In this layout, the material remains in a fixed position, but machinery, tools handling equipment, workers are brought to the place the material. This is in contrast to both product and process layouts. Such a layout may be preferred when the equipment and the machinery is small in number and size, and where the workmen are highly skilled to perform the various small jobs on the product. Fixed position layouts are used in large construction projects, ship building, aircraft manufacturing etc.
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